User321 welcome to Flyertalk and the QR forum. You may find the dashboard helpful when looking for information.

QR do not allow name changes on existing tickets. However they often permit changes/refunds for a fee. This depends upon your ticketing class and country of departure. The change conditions and fees are shown on screen when booking on-line with QR or your travel agent should be able supply them. If you cannot find them then your local QR office should be able to help.

Two years ago I was leading a group where one cancelled and another joined. The tickets allowed changes/cancellation. So I cancelled the one person and had a full refund minus a cancellation fee of about one third of the original ticket price. I was then able to purchase a new ticket.

If one person cancels and does not fly then a no-show fee may be levied if you do not cancel their flights with QR. If the group is a single reservation (PNR) (the 6 character alphanumeric code) then a no-show could result in the entire reservation being cancelled. Unlikely but theoretically possible.

If a ticket is non-refundable then no no-show fee will apply.

Remember that the rules are based upon country of departure.